Law enforcement investigators at the scene of a bullet-riddled black truck on Flagler Lane in Redondo Beach Thursday morning. It appeared that the police car at right and the truck collided and the truck also had several bullet holes in the wiindshield.Photo by Brad Graverson 2-7-13 (Brad Graverson/Staff Photographer)

The hunt for ex-LAPD Officer Christopher Dorner, suspected of killing three people, touched neighborhoods and law enforcement agencies across the region.

Early Thursday morning, multiple police officers arrived at Dorner's last known residence in the 4900 block of Sharon Drive in La Palma, neighbors said.

Neighbor Crystal Lancaster, 28, said up to eight police officers arrived in a van between 5 and 5:30 a.m. She said that Dorner doesn't live in the house but that his mother does, and that her mother and Dorner's mother are good friends.

Police apparently cleared the house and left the scene, she said.

Lancaster said Dorner frequented the house and "was a nice, friendly guy.

Dorner also mentioned attending Norwalk Christian School in Norwalk, where he described striking a fellow first-grader who taunted him with a racial slur. Dorner described it as his "first recollection of racism."

A Norwalk Christian School official on Thursday said Dorner's second-grade portrait was in the school's 1987 yearbook. It was not clear if he was pictured in the yearbooks from other years.

The school decided to close down Thursday for the remainder of the day, and students were being sent home, Norwalk sheriff's Sgt.

Mark Boskovich said.

The principal could not be reached for contact.

Law enforcement agencies were taking precautions because Dorner had targeted police.

The LAPD took all its motorcycles off the street and told officers to ride in cars instead, said Officer Bruce Borihanh, a department spokesman.

He would not say whether extra people are on duty or whether motorcycles are being taken off the streets.

"We're protecting our own deputies, and we're doing whatever needs to be done to ensure the safety of our deputies as well as the public," Whitmore said.

He said the sheriff's Emergency Operations Bureau in East L.A. is up and running, and other agencies are invited to use it to coordinate the search for Dorner.

A California Highway Patrol spokeswoman, Officer Kerri Rivas, says officers in L.A. County are being careful, but the CHP has not ordered motorcycles off the road.

Pasadena police on Thursday took safety measures similar to those enacted by the Los Angeles Police Department.

As in Los Angeles, Pasadena motorcycle officers were taken off their motorcycles, And, he said, no officers will patrol alone.

In Long Beach, police shut down the San Diego (405) Freeway at Bellflower Boulevard at about 8 a.m. Thursday morning after receiving a report of a vehicle matching the description of Dorner's vehicle, said Long Beach Police Department Sgt. Aaron Eaton. Patrol and SWAT officers were on the scene, but it turned out to be a false alarm, Eaton said.

Riverside County Sheriff Deputies form a perimeter near the intersection of Magnolia and Arlington Avenues where a two Riverside Police officers were shot and one was killed February 7, 2013. Ex-LAPD officer Christopher Jordan Dorner, wanted in murder of a college coach and her fiance, and now killing of police officer is believed to be part of a murder manifesto targeting police. A manhunt ensues in the Riverside area. GABRIEL LUIS ACOSTA/STAFF PHOTOGRAPHER. (GABRIEL LUIS ACOSTA)